The field of the invention is casters, and the invention relates more particularly to shopping cart wheels. Such wheels are held in a yoke.
The wheel has a hub about which a thread is formed, and the hub contains a pair of bearing-supporting recesses. An axle is held by the hub and supports the wheel. Unfortunately, such wheels are freely rotatable, typically including ballbearing containing bearings. Because of this, when combined with a parking area slope or wind, the shopping cart can become free sailing, and such carts cause millions of dollars in damage claims each year. Even a minor amount of damage can require store personnel spending many hours of time each year trying to soothe customer tempers and fill out insurance claim reports and forms. The typical property damage claim is $200, and personal injury claims can, of course, run many times more than this. With the introduction of plastic baskets, even more surface area is presented to the wind, and it is expected that damage claims will rise.
While various shopping cart brakes have been devised to eliminate this problem, customers are not prone to using such brakes, and a foolproof system to prevent free sailing carts would really reduce property damage and personal injury.
The amount of friction caused by the wheels should be no more than that needed to prevent the cart from freewheeling for the conditions of the particular outlet. Thus, it would be beneficial to make the amount of friction adjustable. In this way, the cart does not tend to freewheel, and no brake needs to be set by the shopper.